/*
    Gtalk is a videoconference application on the Android Platform.

    Copyright (C) 2009 by Frederic-Charles Barthelery,
                          Jean-Manuel Da Silva,
                          Nikita Kozlov,
                          Philippe Lago,
                          Jean Baptiste Vergely,
                          Vincent Veronis.

    This file is part of Gtalk.

    Gtalk is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Gtalk is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Gtalk.  If not, see <http://www.gnu.org/licenses/>.

    Please send bug reports with examples or suggestions to
    contact@Gtalk-project.com or http://dev.Gtalk-project.com/

    Epitech, hereby disclaims all copyright interest in the program "Gtalk"
    written by Frederic-Charles Barthelery,
               Jean-Manuel Da Silva,
               Nikita Kozlov,
               Philippe Lago,
               Jean Baptiste Vergely,
               Vincent Veronis.

    Nicolas Sadirac, November 26, 2009
    President of Epitech.

    Flavien Astraud, November 26, 2009
    Head of the EIP Laboratory.

 */
package org.lansir.af.gtalk.utils;

import java.io.IOException;
import java.net.ServerSocket;

/**
 * Utility class to get a free port.
 * 
 * @author nikita
 */
public final class FreePort {

	private static final int MAGIC_10 = 10;
	private static final int MAGIC_10000 = 10000;

	/**
	 * Private default constructor.
	 */
	private FreePort() {
	}

	/**
	 * return a free port.
	 * 
	 * @return free socket port.
	 */
	public static int getFreePort() {
		ServerSocket ss;
		int freePort = 0;

		for (int i = 0; i < MAGIC_10; i++) {
			freePort = (int) (MAGIC_10000 + Math.round(Math.random() * MAGIC_10000));
			try {
				ss = new ServerSocket(freePort);
				freePort = ss.getLocalPort();
				ss.close();
				return freePort;
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		try {
			ss = new ServerSocket(0);
			freePort = ss.getLocalPort();
			ss.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return freePort;
	}
}
